The invention relates to a windscreen wiper drive arrangement.
A windscreen wiper drive arrangement is known from DE 299 01 686 U1 comprising a drive motor which is connected via an output shaft to a gear mechanism arranged in a gear mechanism housing. Guided out of the gear mechanism housing is a drive shaft for a windscreen wiper which is driven in an oscillating manner. Conventionally, the drive shaft is guided through an opening in the bodywork or a window, generally the rear window. To avoid water ingress, conventionally a protective sleeve is provided through which the drive shaft is guided in the axial direction. Said protective sleeve is sealed relative to the drive shaft by means of an internal sealing element, for example an O-ring, so that no water is able to run toward the interior along the drive shaft. Moreover, the protective sleeve is sealed by means of an external sealing element, in particular a so-called grommet, relative to the vehicle component through which the drive shaft is guided. It is known to press the protective sleeve provided with an internal cone onto an external cone of the gear mechanism housing, in particular a fixing dome, in the axial direction and thus to produce a non-positive connection between the gear mechanism housing and the protective sleeve.
Such a fastening of the protective sleeve has proved advantageous. As a result of external influences, in particular as a result of continuous shaking movements during travel or during repair work, however, the frictional connection between the protective sleeve and the gear mechanism housing may be released, which may result in the protective sleeve being able to move in the axial direction and/or in the peripheral direction. As a result, firstly there is the risk that the protective sleeve during operation of the windscreen wiper moves in an oscillating manner together with the drive shaft, which leads to greater wear of the internal sealing element. Moreover, the protective sleeve may become skewed such that an effective seal relative to the drive shaft and/or relative to the vehicle component, through which the drive shaft is guided, is no longer ensured. It leads to water ingress, in particular into the gear mechanism and/or motor housing and thus to increased occurrence of wear and an electrical short circuit.